Patent GB-778450-A (GB)
Title: Improvements in dolphins or bumper buoys
IPC: E02B3/28
Filed: 1954-04-22
Abstract: 778,450. Tenders. PAVRY, R. July 20, 1955 [April 22, 1954 ; May 14, 1954], Nos. 11671/54 and 14160/54. Class 113. [Also in Groups X and XXI] A dolphin or bumper buoy comprises a pontoon, a column extending down therethrough, an anchorage member to which the base of the column is connected for tilting movement from the vertical, the pontoon being free to rise and fall on the column when it is vertical, but provided with means for engaging the column under lateral pressure, as by impact from a ship, whereby the pontoon becomes partly submerged by tilting movement of the column so as to provide a resilient resistance and a restoring force. As shown in Figs. 3, 5 a column 10, preferably tubular and water-tight, has a flange 11 secured in a recess 18 in a concrete clump 17 and engaging a metal ring 19. A tubular and water-tight pontoon 12 has a superstructure 13 joined to form a hub 14 slidable on the column 10, the hub having a lining of frictional material to increase the grip of the hub 14 on the column 10 under lateral pressure as from a ship's hull 25 when the column 10 will pivot about the point 26 and the pontoon be partly submerged. Tenders 16 and suitable rings, shackles, bollards or other mooring devices may be fitted on the pontoon 12 of the upper part of the column 10. The clump 17 is preferably hollow, having a buoyancy chamber 20 with an inflation and drainage valve 21 and drainage pipe 22 fitted in a detachable manhole cover 23, and the whole may be floated into position and the clump lowered by allowing air to escape from the chamber 20. If no chamber 20 is provided, suitable tackle for raising and lowering the clump may be provided. As shown in Fig. 9, a pair of columns 44 with flanges 46 anchored in recesses in clumps 45 extend through pipes 47 in a single pontoon 43, the pipes being lined with frictional material to increase their grip on the columns under lateral pressure. A series of pontoons 43 are used to support piers 42 which carry the spans 41 of a floating bridge. The buoyancy of the columns 44 and pontoons 43 will not only act to absorb the impact from a ship but will also resist tidal and like movements tending to carry the pontoons up or down the waterway. Each pontoon 43 may be divided to a number of separate pontoons each with its own column 44 and/or the clumps 45 may be combined into one. The pontoons supporting the bridge piers may be separate from the pontoons on the columns, which are then attached to the main pontoons. As shown in Fig. 8, a column 30 with a flange 31 is anchored under an annular casting 39 having projecting arms 40 with flanges for bolting to the piles 36 of a wharf or pier 33, the column 30 extending through a cage 34 secured to a rectangular pontoon 35 guided between the piles 36, the cage 34 being lined with frictional material and having a part, fitted with a fender 38, which projects beyond the face of the wharf, to be engaged by the side of a ship. In a modification, the ring 31 is engaged in a clump similar in shape to clumps 17, 45 and which may be of concrete or may be connected to the wharf by chains or other means.